ARTICLE | doi:10.20944/preprints202007.0675.v1
Online: 28 July 2020 (10:20:32 CEST)
Urban mobility is experiencing a profound change. On the one hand, mobility patterns are becoming more complex, and typical home-work-home travel is no longer the rule, as journeys now tend to connect multiple points in a rather inconstant pattern. This has changed the approach to transport planning, in that the existing transportation planning and operation approaches have been focussed on the ability to identify typical home-work/school-home travel and subsequently plan the transport system accordingly. The traditional approach has been: forecast -> plan -> deliver, as new mobility solutions are emerging. These are characterised by greater flexibility, in that they take advantage of the “sharing concept” and simultaneously provide solutions that have lower GHG emissions. Urban mobility follows a fuzzier pattern, with even the urban transportation system behaving like an active organism, where solutions are often quickly replaced. This dynamic and evolving environment raises several new challenges at different levels. The best digital solution system is the Mobility-as-a-Service (MaaS) one. This system transforms the physical transportation system into a commodity and takes advantage of the internet of things (IoT). However, the onset of MaaS solutions is anything but linear. Several business models have emerged, with different partners originating from different industries (e.g., technological, transport operators, infrastructure managers, etc.) developing their own solutions, often in competition with others. It is not unusual to find different MaaS solutions in the same city, which integrate different solutions.
ARTICLE | doi:10.20944/preprints202110.0201.v1
Subject: Engineering, Civil Engineering Keywords: cost estimation; cost deviation; financial crisis; promotor-contractor; statistical modelling
Online: 13 October 2021 (12:48:56 CEST)
For the majority of the contractual arrangements used in construction projects, the owner is not responsible for the cost deviations due to the variability of labor productivity or material price, amongst many other aspects. Consequently, the cost performance of a project may be entirely distinct for the owner and the contractor. Since the majority of the quantitative research on cost estimation and deviation found in the literature adopts the owners’ perspective, this research provides a contribution towards modelling costs and cost deviation from a contractors’ perspective. From an initial sample of 13 residential building and 10 office building projects, it was possible to develop models for cost estimation at the early stage of development including both endogenous and exogenous variables. Although the sample is relatively small, the authors were able to fully analyze all the cost data, using no secondary sources of data (very frequent in cost modelling studies). The statistically significant variables in the cost estimation models were the areas above and below ground and the years following the 2008 financial crisis, including the international bailout (2011-2014) period. For estimating the unit cost, a nonlinear model was obtained with the number of underground and total floor, the floor ratio and the years following the 2008 financial crisis, including the international bailout (2011-2014) period as predictors. For the office buildings, it was also found a statistically significant correlation between the cost deviation and the number of underground floors.